Primary Progressive Aphasia (PPA) is a neurodegenerative syndrome with impaired language as most prominent symptom, in particular impaired word retrieval at the early stage, yet still without established treatment. We evaluated the efficacy of a therapy for word retrieval in PPA using a series of single case experimental designs in three patients. We predicted that treated items should be retrieved more easily, compared to untreated items, bearing in mind that the default pattern in a neurodegenerative condition is for a worsening of performance. The patients were 59, 64, and 69 years old and had been diagnosed with svPPA (2 cases) and lvPPA, respectively, after extensive diagnostic work-up (including CSF analysis, cMRT, FDG-PET, FBB-PET). Items for treatment (n≥120) were selected individually for each patient. Two matched sets of words (n≥30 each) were trained with an errorless learning technique using delivery via PC for two (one set) and successively four weeks (other set). The remaining stimuli (n≥60) served as control set. Outcome measures were accuracy of confrontation naming for treated and untreated items and carry-over into spontaneous speech, assessed in a semi-structured interview. One patient (svPPA) showed significant improvement in naming performance for treated but not for untreated items. He continued practicing for another six months, resulting in further improvement of naming. The other two patients (svPPA & lvPPA) showed no significant change. Our study suggests that in a minority of patients naming skills may benefit from dedicated treatment, even if the ecological validity of this effect remains to be proven.